add insertion sort (#1225)

test/unit/stdlib/sort/insertionsort.c3

@@ -0,0 +1,96 @@
+module sort_test @test;
+import std::sort;
+import sort::check;
+import std::collections::list;
+
+fn void insertionsort()
+{
+    int[][] tcases = {
+        {},
+        {10, 3},
+        {3, 2, 1},
+        {1, 2, 3},
+        {2, 1, 3},
+    };
+
+    foreach (tc : tcases)
+    {
+        sort::insertionsort(tc);
+        assert(check::int_ascending_sort(tc));
+    }
+}
+
+fn void insertionsort_with_ref()
+{
+    int[][] tcases = {
+        {},
+        {10, 3},
+        {3, 2, 1},
+        {1, 2, 3},
+        {2, 1, 3},
+    };
+
+    foreach (tc : tcases)
+    {
+        sort::insertionsort(tc, &sort::cmp_int_ref);
+        assert(check::int_ascending_sort(tc));
+    }
+}
+
+fn void insertionsort_with_value()
+{
+    int[][] tcases = {
+        {},
+        {10, 3},
+        {3, 2, 1},
+        {1, 2, 3},
+        {2, 1, 3},
+    };
+
+    foreach (tc : tcases)
+    {
+        sort::insertionsort(tc, &sort::cmp_int_value);
+        assert(check::int_ascending_sort(tc));
+    }
+}
+
+fn void insertionsort_with_lambda()
+{
+    int[][] tcases = {
+        {},
+        {10, 3},
+        {3, 2, 1},
+        {1, 2, 3},
+        {2, 1, 3},
+    };
+
+    foreach (tc : tcases)
+    {
+        sort::insertionsort(tc, fn int(int a, int b) => a - b);
+        assert(check::int_ascending_sort(tc));
+    }
+}
+
+def InsertionSortTestList = List(<int>);
+
+fn void insertionsort_list()
+{
+    InsertionSortTestList list;
+    list.temp_init();
+    list.add_array({ 2, 1, 3});
+    sort::insertionsort(list, &sort::cmp_int_value);
+    assert(check::int_ascending_sort(list.array_view()));
+}
+
+module sort::check;
+
+fn bool int_ascending_sort(int[] list)
+{
+    int prev = int.min;
+    foreach (x : list)
+    {
+        if (prev > x) return false;
+        prev = x;
+    }
+    return true;
+}